A spacecraft can include various types of sensors for capturing images, computers for receiving and processing signals from the sensors, and communication modules for transmitting data. A Stirling cycle cryogenic cooler can be used to remove heat from the sensors and cool the sensors to very low temperatures, in the range of 5 Kelvin (K)-100K. The cryogenic cooler includes several moving components, such as one or more compressor pistons, an expander piston (also referred to as a displacer piston), balancer mass that counteracts the forces of the expander piston. Each of these moving components is driven by a linear motor, which is part of the moving component assembly. For example, a piston assembly includes a wire coil wound around a bobbin that annularly surrounds the shaft portion of the piston; the piston assembly sits in a magnetic field, and upon receiving current through the coil, an electromagnetic force drives the piston in a linear motion. These moving components generate vibrations that will limit the performance of the various sensors if the vibrations are not reduced. The moving components generate vibrations at the fundamental motor drive frequency, as well as many of the harmonics of the motor drive frequency. The Stirling cycle cryogenic cooler can include an adaptive feed-forward (AFF) vibration control system to suppress the vibrations associated with moving components of the cryogenic cooler at the fundamental frequency and higher harmonics.
As an example, a Stirling cycle cryogenic cooler system can include piezoelectric force transducers that sense physical vibrations that the cryocooler creates and that generate electrical output signals corresponding to the sensed vibrations. The AFF control system includes processing circuitry that analyzes the transducers' output signals and that generates a cancellation signal which is output to the motor drive circuits. In response to receiving the cancellation signal, the pistons and balancer mass are driven in such a way as to substantially cancel the vibration forces of the fundamental frequency and many of its harmonics.